如何在 Symfony 2.0 AJAX 应用程序中将 Doctrine 实体编码为 JSON？

我正在开发游戏应用程序，并使用 Symfony 2.0。我对后端有许多 AJAX 请求。更多的响应正在将实体转换为 JSON。例如:

class DefaultController extends Controller
{
public function launchAction()
{
$user = $this->getDoctrine()
->getRepository('UserBundle:User')
->find($id);


// encode user to json format
$userDataAsJson = $this->encodeUserDataToJson($user);
return array(
'userDataAsJson' => $userDataAsJson
);
}


private function encodeUserDataToJson(User $user)
{
$userData = array(
'id' => $user->getId(),
'profile' => array(
'nickname' => $user->getProfile()->getNickname()
)
);


$jsonEncoder = new JsonEncoder();
return $jsonEncoder->encode($userData, $format = 'json');
}
}

我的所有控制器都做同样的事情: 获取一个实体并将其中的一些字段编码为 JSON。我知道我可以使用规范化程序并对所有实体进行编码。但是，如果一个实体与其他实体之间存在循环链接，该怎么办呢？还是实体图很大？你有什么建议吗？

我考虑了一些实体的编码模式... ... 或者使用 NormalizableInterface来避免循环... ... ,

134425 次浏览
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You can automatically encode into Json, your complex entity with:

use Symfony\Component\Serializer\Serializer;
use Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer;
use Symfony\Component\Serializer\Encoder\JsonEncoder;


$serializer = new Serializer(array(new GetSetMethodNormalizer()), array('json' => new
JsonEncoder()));
$json = $serializer->serialize($entity, 'json');
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I just had to solve the same problem: json-encoding an entity ("User") having a One-To-Many Bidirectional Association to another Entity ("Location").

I tried several things and I think now I found the best acceptable solution. The idea was to use the same code as written by David, but somehow intercept the infinite recursion by telling the Normalizer to stop at some point.

I did not want to implement a custom normalizer, as this GetSetMethodNormalizer is a nice approach in my opinion (based on reflection etc.). So I've decided to subclass it, which is not trivial at first sight, because the method to say if to include a property (isGetMethod) is private.

But, one could override the normalize method, so I intercepted at this point, by simply unsetting the property that references "Location" - so the inifinite loop is interrupted.

In code it looks like this:

class GetSetMethodNormalizer extends \Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer {


public function normalize($object, $format = null)
{
// if the object is a User, unset location for normalization, without touching the original object
if($object instanceof \Leonex\MoveBundle\Entity\User) {
$object = clone $object;
$object->setLocations(new \Doctrine\Common\Collections\ArrayCollection());
}


return parent::normalize($object, $format);
}


}
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最佳答案

Another option is to use the JMSSerializerBundle. In your controller you then do 

$serializer = $this->container->get('serializer');
$reports = $serializer->serialize($doctrineobject, 'json');
return new Response($reports); // should be $reports as $doctrineobject is not serialized

You can configure how the serialization is done by using annotations in the entity class. See the documentation in the link above. For example, here's how you would exclude linked entities:

 /**
* Iddp\RorBundle\Entity\Report
*
* @ORM\Table()
* @ORM\Entity(repositoryClass="Iddp\RorBundle\Entity\ReportRepository")
* @ExclusionPolicy("None")
*/
....
/**
* @ORM\ManyToOne(targetEntity="Client", inversedBy="reports")
* @ORM\JoinColumn(name="client_id", referencedColumnName="id")
* @Exclude
*/
protected $client;
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I found the solution to the problem of serializing entities was as follows:

#config/config.yml


services:
serializer.method:
class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
serializer.encoder.json:
class: Symfony\Component\Serializer\Encoder\JsonEncoder
serializer:
class: Symfony\Component\Serializer\Serializer
arguments:
- [@serializer.method]
- {json: @serializer.encoder.json }

in my controller:

$serializer = $this->get('serializer');


$entity = $this->get('doctrine')
->getRepository('myBundle:Entity')
->findOneBy($params);




$collection = $this->get('doctrine')
->getRepository('myBundle:Entity')
->findBy($params);


$toEncode = array(
'response' => array(
'entity' => $serializer->normalize($entity),
'entities' => $serializer->normalize($collection)
),
);


return new Response(json_encode($toEncode));

other example:

$serializer = $this->get('serializer');


$collection = $this->get('doctrine')
->getRepository('myBundle:Entity')
->findBy($params);


$json = $serializer->serialize($collection, 'json');


return new Response($json);

you can even configure it to deserialize arrays in http://api.symfony.com/2.0

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With php5.4 now you can do :

use JsonSerializable;


/**
* @Entity(repositoryClass="App\Entity\User")
* @Table(name="user")
*/
class MyUserEntity implements JsonSerializable
{
/** @Column(length=50) */
private $name;


/** @Column(length=50) */
private $login;


public function jsonSerialize()
{
return array(
'name' => $this->name,
'login'=> $this->login,
);
}
}

And then call

json_encode(MyUserEntity);
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I had the same problem and I chosed to create my own encoder, which will cope by themself with recursion.

I created classes which implements Symfony\Component\Serializer\Normalizer\NormalizerInterface, and a service which holds every NormalizerInterface.

#This is the NormalizerService


class NormalizerService
{


//normalizer are stored in private properties
private $entityOneNormalizer;
private $entityTwoNormalizer;


public function getEntityOneNormalizer()
{
//Normalizer are created only if needed
if ($this->entityOneNormalizer == null)
$this->entityOneNormalizer = new EntityOneNormalizer($this); //every normalizer keep a reference to this service


return $this->entityOneNormalizer;
}


//create a function for each normalizer






//the serializer service will also serialize the entities
//(i found it easier, but you don't really need it)
public function serialize($objects, $format)
{
$serializer = new Serializer(
array(
$this->getEntityOneNormalizer(),
$this->getEntityTwoNormalizer()
),
array($format => $encoder) );


return $serializer->serialize($response, $format);
}

An example of a Normalizer :

use Symfony\Component\Serializer\Normalizer\NormalizerInterface;


class PlaceNormalizer implements NormalizerInterface {


private $normalizerService;


public function __construct($normalizerService)
{
$this->service = normalizerService;


}


public function normalize($object, $format = null) {
$entityTwo = $object->getEntityTwo();
$entityTwoNormalizer = $this->service->getEntityTwoNormalizer();


return array(
'param' => object->getParam(),
//repeat for every parameter
//!!!! this is where the entityOneNormalizer dealt with recursivity
'entityTwo' => $entityTwoNormalizer->normalize($entityTwo, $format.'_without_any_entity_one') //the 'format' parameter is adapted for ignoring entity one - this may be done with different ways (a specific method, etc.)
);
}


}

In a controller :

$normalizerService = $this->get('normalizer.service'); //you will have to configure services.yml
$json = $normalizerService->serialize($myobject, 'json');
return new Response($json);

The complete code is here : https://github.com/progracqteur/WikiPedale/tree/master/src/Progracqteur/WikipedaleBundle/Resources/Normalizer

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To complete the answer: Symfony2 comes with a wrapper around json_encode: Symfony/Component/HttpFoundation/JsonResponse

Typical usage in your Controllers:

...
use Symfony\Component\HttpFoundation\JsonResponse;
...
public function acmeAction() {
...
return new JsonResponse($array);
}
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in Symfony 2.3

/app/config/config.yml

framework:
# сервис конвертирования объектов в массивы, json, xml и обратно
serializer:
enabled: true


services:
object_normalizer:
class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
tags:
# помечаем к чему относится этот сервис, это оч. важно, т.к. иначе работать не будет
- { name: serializer.normalizer }

and example for your controller:

/**
* Поиск сущности по ИД объекта и ИД языка
* @Route("/search/", name="orgunitSearch")
*/
public function orgunitSearchAction()
{
$array = $this->get('request')->query->all();


$entity = $this->getDoctrine()
->getRepository('IntranetOrgunitBundle:Orgunit')
->findOneBy($array);


$serializer = $this->get('serializer');
//$json = $serializer->serialize($entity, 'json');
$array = $serializer->normalize($entity);


return new JsonResponse( $array );
}

but the problems with the field type \DateTime will remain.

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This is more an update (for Symfony v:2.7+ and JmsSerializer v:0.13.*@dev), so to avoid that Jms tries to load and serialise the whole object graph ( or in case of cyclic relation ..)

Model:

use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation\ExclusionPolicy;
use JMS\Serializer\Annotation\Exclude;
use JMS\Serializer\Annotation\MaxDepth; /* <=== Required */
/**
* User
*
* @ORM\Table(name="user_table")
///////////////// OTHER Doctrine proprieties //////////////
*/
public class User
{
/**
* @var integer
*
* @ORM\Column(name="id", type="integer")
* @ORM\Id
* @ORM\GeneratedValue(strategy="AUTO")
*/
protected   $id;


/**
* @ORM\ManyToOne(targetEntity="FooBundle\Entity\Game")
* @ORM\JoinColumn(nullable=false)
* @MaxDepth(1)
*/
protected $game;
/*
Other proprieties ....and Getters ans setters
......................
......................
*/

Inside an Action:

use JMS\Serializer\SerializationContext;
/* Necessary include to enbale max depth */


$users = $this
->getDoctrine()
->getManager()
->getRepository("FooBundle:User")
->findAll();


$serializer = $this->container->get('jms_serializer');
$jsonContent = $serializer
->serialize(
$users,
'json',
SerializationContext::create()
->enableMaxDepthChecks()
);


return new Response($jsonContent);
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If you are using Symfony 2.7 or above, and don't want to include any additional bundle for serializing, maybe you can follow this way to seialize doctrine entities to json -

  1. In my (common, parent) controller, I have a function that prepares the serializer

    use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactory;
use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Serializer;


// -----------------------------


/**
* @return Serializer
*/
protected function _getSerializer()
{
$classMetadataFactory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));
$normalizer           = new ObjectNormalizer($classMetadataFactory);


return new Serializer([$normalizer], [new JsonEncoder()]);
}

  2. Then use it to serialize Entities to JSON 

    $this->_getSerializer()->normalize($anEntity, 'json');
$this->_getSerializer()->normalize($arrayOfEntities, 'json');

Done!

But you may need some fine tuning. For example -

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When you need to create a lot of REST API endpoints on Symfony, the best way is to use the following stack of bundles:

  1. JMSSerializerBundle for the serialization of Doctrine entities
  2. FOSRestBundle bundle for response view listener. Also, it can generate definitions of routes based on controller/action name.
  3. NelmioApiDocBundle to auto-generate online documentation and Sandbox(which allows testing endpoint without any external tool).

When you configure everything properly, you entity code will look like this:

use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation as JMS;


/**
* @ORM\Table(name="company")
*/
class Company
{


/**
* @var string
*
* @ORM\Column(name="name", type="string", length=255)
*
* @JMS\Expose()
* @JMS\SerializedName("name")
* @JMS\Groups({"company_overview"})
*/
private $name;


/**
* @var Campaign[]
*
* @ORM\OneToMany(targetEntity="Campaign", mappedBy="company")
*
* @JMS\Expose()
* @JMS\SerializedName("campaigns")
* @JMS\Groups({"campaign_overview"})
*/
private $campaigns;
}

Then, code in controller:

use Nelmio\ApiDocBundle\Annotation\ApiDoc;
use FOS\RestBundle\Controller\Annotations\View;


class CompanyController extends Controller
{


/**
* Retrieve all companies
*
* @View(serializerGroups={"company_overview"})
* @ApiDoc()
*
* @return Company[]
*/
public function cgetAction()
{
return $this->getDoctrine()->getRepository(Company::class)->findAll();
}
}

The benefits of such a set up are:

  • @JMS\Expose() annotations in the entity can be added to simple fields, and to any type of relations. Also, there is the possibility to expose the result of some method execution (use annotation @JMS\VirtualProperty() for that)
  • With serialization groups, we can control exposed fields in different situations.
  • Controllers are very simple. The action method can directly return an entity or array of entities, and they will be automatically serialized.
  • And @ApiDoc() allows testing the endpoint directly from the browser, without any REST client or JavaScript code
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Now you can also use Doctrine ORM Transformations to convert entities to nested arrays of scalars and back

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The accepted answer is correct but if You'll need to serialize a filtered subset of an Entity , json_encode is enough:

Consider this example:

class FileTypeRepository extends ServiceEntityRepository
{


const ALIAS = 'ft';
const SHORT_LIST = 'ft.name name';


public function __construct(ManagerRegistry $registry)
{
parent::__construct($registry, FileType::class);
}


public function getAllJsonFileTypes()
{
return json_encode($this->getAllFileTypes());
}


/**
* @return array
*/
public function getAllFileTypes()
{
$query = $this->createQueryBuilder(self::ALIAS);
$query->select(self::SHORT_LIST);
return $query->getQuery()->getResult();
}
}






/** THIS IS ENOUGH TO SERIALIZE AN ARRAY OF ENTITIES SINCE the doctrine SELECT will remove complex data structures from the entities itself **/
json_encode($this->getAllFileTypes());

Short note: Tested at least on Symfony 5.1


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